XL 2016 Ouvrir un fichier Word existant depuis excel

Set WordDoc = WordApp.Documents.Add

Sub ouvrir_word()
Dim WordApp As Object, WordDoc As Object, Rng As Object
Dim Rep As String, Ndf As String, Logo As String
Dim i As Integer, j As Integer
Dim Total As Single


                  
    On Error GoTo errhdlr
    Rep = "D:\VBA\GESTION\"
    If Not Exist_Rep(Rep) Then
    MkDir Rep
    Else
    MsgBox "..."
    End If
    

    Set WordApp = CreateObject("Word.Application")
    Set WordDoc = WordApp.Documents.Add

   ' WordApp.Documents.Open "D:\VBA\GESTION\TEST.docx"
    
 
    
    Ndf = Rep & "Fiche_" & Format(Now(), "yyyyMMdd_hhmm") & ".docx"
    
    With WordDoc
        ' Mise en page : Marges
        With .PageSetup
            .LeftMargin = WordApp.CentimetersToPoints(1.5)
            .RightMargin = WordApp.CentimetersToPoints(1.5)
            .TopMargin = WordApp.CentimetersToPoints(2)
            .BottomMargin = WordApp.CentimetersToPoints(2)
        End With
        ''----
        '----etc--'
        
        
        end sub